AMCEBJS OF THE MOUTH. 231 



MORPHOLOGY. This species is relatively small, 

 measuring from 6 to 32 microns in diameter, the 

 average measurement being 15 microns. It has a 

 distinct ectoplasm, while the endoplasm appears quite 

 granular and is filled with vacuoles. The ectoplasm 

 is seldom visible unless the organism is moving, when 

 it appears clear and hyaline and is little more re- 

 fractive than the endoplasm. The nucleus is well 

 defined, spherical or oval in shape, and surrounded 

 by a thick greenish nuclear membrane containing 

 much refractive material resembling chromatin. A 

 small centriole, surrounded by a clear area and a 

 small chromatin zone, is situated near the centre of 

 the nucleus. 



MotiUty is sluggish in character and is produced 

 by the extrusion of short, blunt, ectoplasmic pseudo- 

 podia into which the endoplasm flows. The motility 

 is not as marked as in Entamceba histolytica or 

 Entamceba tetragena, but is more marked than in 

 Entamceba coli. 



Reproduction occurs by simple division, the 

 nucleus dividing by mitosis, and a nuclear spindle is 

 often observed. Schizogony has been described as 

 occurring in this species, the nucleus distributing 

 chromatin to the cytoplasm, which eventually divides 

 into small amoebae, each containing a small amount 

 of nuclear chromatin. 



